Matplotlib:每15分钟xticks,从小时开始

Question

我试图用温度对时间绘制温度值,格式为HH:MM.我能够将xticks设置为每15分钟重复一次,但第一次打勾是第一次(例如04:40).

有没有办法在每小时和同时的四分之一小时(04:45,05:00,05:15等)上移动刻度？我目前的代码如下:

import matplotlib.pyplot as plt
import matplotlib.dates as md
import datetime as dt

## Dummy times and temperatures
time = [dt.datetime(2017,2,15,4,40),dt.datetime(2017,2,15,4,46),dt.datetime(2017,2,15,4,52),dt.datetime(2017,2,15,4,58),dt.datetime(2017,2,15,5,4),dt.datetime(2017,2,15,5,10)]
temp = [7, 8, 9, 10, 11, 12]

## Plot the data
figtemp, ax = plt.subplots(1, 1)
ax.plot(time, temp)

## Set time format and the interval of ticks (every 15 minutes)
xformatter = md.DateFormatter('%H:%M')
xlocator = md.MinuteLocator(interval = 15)

## Set xtick labels to appear every 15 minutes
ax.xaxis.set_major_locator(xlocator)

## Format xtick labels as HH:MM
plt.gcf().axes[0].xaxis.set_major_formatter(xformatter)

Answer 1

你可以告诉MinuteLocator只使用几分钟0,15,30,45使用byminute的说法.

xlocator = md.MinuteLocator(byminute=[0,15,30,45], interval = 1)

Answer 2

使用Axes.set_xticklabels，

labels = ['04:45', '05:00', '05:15']
plt.gca().set_xticklabels(labels)

它产生，

将时间改为同时刻钟，

import datetime

list_dt = [ datetime.datetime(2017,2,15,4,40),
            datetime.datetime(2017,2,15,4,46),
            datetime.datetime(2017,2,15,4,52),
            datetime.datetime(2017,2,15,4,58),
            datetime.datetime(2017,2,15,5,4),
            datetime.datetime(2017,2,15,5,10)]

adjust_list_dt = list()

for dt in list_dt:
    print(dt.minute//15)

    if dt.minute % 15 == 0:
        adjust_minutes = dt.minute
    else:
        adjust_minutes = (dt.minute//15 + 1)*15

    if adjust_minutes == 60:
        adjust_list_dt.append(dt.replace(hour=dt.hour+1, minute=0))
    else:
        adjust_list_dt.append(dt.replace(minute=adjust_minutes))

print(adjust_list_dt)
# Output
'''
[datetime.datetime(2017, 2, 15, 4, 45), 
 datetime.datetime(2017, 2, 15, 5, 0),
 datetime.datetime(2017, 2, 15, 5, 0), 
 datetime.datetime(2017, 2, 15, 5, 0), 
 datetime.datetime(2017, 2, 15, 5, 15), 
 datetime.datetime(2017, 2, 15, 5, 15)]
'''